Conventionally, in an LTO (Linear Tape-Open) device used by a general purpose computer system, when additionally recording data on a cartridge medium, a data volume recordable on the cartridge medium is managed.
For example, application software installed in a general purpose computer system reads data of an End-Of-Volume label recorded on a cartridge medium, and calculates a non-recorded data volume from the nominal maximum recording volume of the cartridge medium, and a data volume read from the cartridge medium.
Alternatively, an operator himself/herself loads a cartridge medium on a tape drive, reads a data volume currently recorded in a CM (Cartridge Memory), calculates a recorded data volume and a non-recorded data volume, and creates a history book of the cartridge medium.    Patent Document 1: International Publication Pamphlet No. WO 97/17652    Patent Document 2: Japanese Laid-open Patent Publication No. 2007-104006
However, the problem with the conventional technology is that it is difficult to manage the non-recorded data volume of the cartridge medium efficiently.
Specifically, all the methods of the conventional technology adopt a technique of loading the cartridge medium on the tape drive. For this reason, time to load the cartridge medium on the tape drive occurs whenever calculating the non-recorded data volume.